Think of the hundreds of people you can remember ever having met. Add those individuals--such as celebrities, politicians and other famous figures--whose faces you know well only from movies, TV and photographs. Is it possible that each of those individuals, along with thousands of other objects you can easily recognize from earlier encounters, could be captured in your memory by its own personal brain cell?

Perhaps. A recent study published in the journal Nature by scientists at the California Institute of Technology and the University of California, Los Angeles, suggests that our brains use far fewer cells to interpret any given image than previously believed. For instance, researchers discovered a "Bill Clinton cell" that responds almost exclusively to the former president. Another neuron fires only when the actor Halle Berry comes into view.